Vertical full-rotation shuttle, stitches made by vertical full-rotation shuttle and stitch forming method

ABSTRACT

The present invention relates to a vertical full-rotation shuttle, which leads a feed-side string portion of a needle thread loop to be wound around and hooked to a bobbin thread from one side of a bobbin case to the other side thereof according to the rotation of a hook part, and leads a stitch-side string portion of a needle thread to the surface of the bobbin case at one side of the bobbin case, such that the feed-side string portion of the needle thread turns the bobbin thread around and the needle thread loop jumps over the bobbin case so as to form complete stitches

BACKGROUND OF THE INVENTION Technical Field

The present invention relates to a vertically fully rotating shuttle provided in a sewing machine and an embroidering machine for sewing cloth and leather, a stitch made by the vertically fully rotating shuttle, and a method of manufacturing a stitch.

Related Art

FIG. 1 is a perspective view illustrating an existing vertically fully rotating shuttle 1. The vertically fully rotating shuttle 1 includes an outer shuttle 2 fixed to a driving shaft 5, an inner shuttle 3 incased in the outer shuttle 2, and a bobbin case 4 detachably mounted in the inner shuttle 3 to incase a bobbin around which a bobbin thread 7 are wound.

The driving shaft 5 is fixed to a base end part 2 a of the outer shuttle 2 so that the outer shuttle 2 is turned around a rotation axis L1 by the driving shaft 5. A hook 6 is provided on the outer circumference of the outer shuttle 2 to capture a needle thread 10 inserted through a needle 11, and a thread guide 8 is provided along the outer circumference of the outer shuttle 2 outside the hook 6.

The inner shuttle 3 is encased in the outer shuttle to rotate freely in the state where the rotation caused by the rotation of the outer shuttle 2 is blocked. A flange 12 is formed at an open end side of the inner shuttle 3 such that one side of the base end part 2 a of the outer shuttle 2 of the flange 12 is provided with a needle falling hole 9 through which the needle 11 is inserted.

The needle 11 reciprocates vertically through the needle falling hole 9 almost vertical to the rotation axis L1 of the outer shuttle 2. The outer shuttle 2, as pointed by an arrow A1 when viewing from the open end of the outer shuttle 2, rotates counterclockwise, and the hook 6 captures the needle thread 10 toward the base end part 2 a of the outer shuttle 2 with respect to the traveling path of the needle 11 so that stitches are formed by the bobbin thread 7 and the needle thread 10.

FIG. 2 is a view schematically illustrating that a process of forming a strand when two sheets of cloth 15 and 16 to be sewed advance and are sewed. Moreover, in FIG. 2 the outer shuttle 2 and the inner shuttle 3 are omitted. When the respective sheets of cloth 15 and 16 go forward and are sewed, in other words, the respective sheets of cloth 15 and 16 is transported toward an arrow B1 in the same direction as the traveling direction when the hook 6 captures the needle thread 10, the needle thread 10, as illustrated in (1) of FIG. 2, is captured by the hook 6 at the upstream in the rotational direction A1 of the outer shuttle 2 rather than the bobbin thread 7 shifted to the base end part 2 a of the outer shuttle 2. The needle thread 10 captured by hook 6 forms a needle thread loop so that the feeding thread portion 10 a of the needle thread 10 is guided and wound around the inner shuttle 3 between the inner shuttle 3 encasing the bobbin case 4 and the outer shuttle 2 by the rotation of the hook 6, while a stitch thread portion 10 b of the needle thread 10 is guided to the surface of the bobbin case 4 of the open end side of the inner shuttle 3 such that the needle thread loop does thread-pumping as illustrated in (2) of FIG. 2.

By doing so, the needle thread loop doing the thread-pumping is decreased when the feeding thread portion 10 a of the needle thread 10 is pulled up by a thread take-up lever (not shown) provided above the vertically fully rotating shuttle 1, and as illustrated in (3) of FIG. 2, and is wound around the bobbin thread 7. When the feeding portion 10 a of the needle thread 10 is further pulled up by the thread take-up lever, the bobbin thread 7 and the needle thread 10 are caught by each other near a seam of the two sheets of cloth 15 and 16 to form a stitch. By repeating the formation of a series of stitches as described above, as illustrated in (4) of FIG. 2, a continuous final stitches 18 are formed.

According to the above-described existing vertically fully shuttle 1, since the feeding portion 10 a of the needle thread 10 is guided and wound around the inner shuttle 3 between the outer shuttle 2 and the inner shuttle 3 which accommodate the bobbin case 4 when the hook 6 rotates, the stitch-sided thread portion 10 b of the needle thread 10 is guided to the surface of the bobbin case 4 of the open end side of the inner shuttle 3 and the needle thread loop is jumped, the stitch-sided thread portion 10 b of the needle thread 10 turns around the bobbin thread 7 to form the stitch and the final stitch is completed so that the final stitch 18 does not become a lock stitch and sewing quality is inferior.

Moreover, according to the existing vertically rotating shuttle 1, as illustrated in FIG. 3, when viewing in the direction where the bobbin thread 10 is stitched, since the needle thread 10 surrounds around the bobbin thread 7 from the upstream to the downstream and twisted in the ring shape continuously, no portion of the needle thread 10 covers the bobbin thread 7 directly over the respective stitches, and the bobbin thread 7 squeezes out between the loop of the needle thread 10, the final stitch is released when any one of the needle thread 10 and the bobbin thread 7 is cut off or the bobbin thread 7 is pull and tensed.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above problem, and the present invention provides a vertically fully rotating shuttle in which a feeding thread portion of a needle thread loop is guided and wound around a bobbin thread from one side to the other side of a bobbin case by the rotation of a hook, a stitch-sided thread portion of the needle thread is guided to the surface of the bobbin case in one end side of the bobbin case and turns around the bobbin thread, and the needle thread loop jumps the bobbin case such that the final stitch become a lock stitch.

According to the related art, the stitch-sided thread portion of the needle thread loop turns around the bobbin thread and the needle thread loop jumps, however, according to the present invention, since the feeding thread portion of the needle thread loop turns around the bobbin thread and the needle thread loop jumps by the above-described vertically fully rotating shuttle, the final stitch becomes a lock stitch so that the sewing product of uniform quality can be obtained.

Furthermore, according to the vertically fully rotating shuttle of the present invention, when viewing in the direction where the bobbin thread is stitched, the needle thread surrounds around the bobbin thread from the downstream to the upstream and is twisted to form a not-opened ring-shaped stitch, a portion of the needle thread covers the bobbin thread from directly above the respective stitches such that the bobbin thread cannot squeeze between the needle thread loop, thus the final stitch cannot be released when any one of the needle thread and the bobbin thread is cut off or tensed.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, features and advantages of the present invention will be more apparent from the following detailed description in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view illustrating an existing vertically fully rotating shuttle;

FIG. 2 is a view schematically illustrating that a process of forming a stitch during forward sewing using the vertically fully rotating shuttle of FIG. 1;

FIG. 3 is an enlarged view of the final stitch of FIG. 2;

FIG. 4 is a sectional view illustrating a vertically fully rotating shuttle according to an embodiment of the present invention;

FIG. 5 is a perspective view illustrating the vertically fully rotating shuttle of FIG. 4;

FIG. 6 is an exploded perspective view illustrating the vertically fully rotating shuttle of FIG. 4;

FIG. 7 is a view schematically illustrating a process of forming a stitch when forward sewing using the vertically fully rotating shuttle of FIG. 4; and

FIG. 8 is a view schematically illustrating shapes and firmness of the existing final stitch and the final stitch according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, exemplary embodiments of a vertically fully rotating shuttle according to the present invention are described in detail with reference to FIGS. 4 to 8.

In the following description, one side of a housing is a side adjacent to a power transmission rotation unit in the direction of a rotation central axis of the power transmission rotation unit and the other side of the housing is a side not adjacent to a power transmission rotation unit in the direction of a rotation central axis of the power transmission rotation unit.

FIG. 4 shows a sectional view of a vertically fully rotating shuttle according to an embodiment of the present invention.

The vertically fully rotating shuttle, as illustrated in FIGS. 4 to 6, includes a housing 100 coupled to a main body of a sewing machine and an embroidering machine; a power transmission rotation unit 200 fixedly circumscribing a rotation shaft (not shown) provided to the sewing machine and the embroidering machine and disposed at one side of the housing 100 to rotate around a central axis L of the rotation shaft; a hook body 300 rotatably installed in the housing 100 in a state that an edge facing the other side of the housing 100 is in contact with a step 140 formed on the center of the inner circumference of the housing 100 and extending to the other side of the housing and being latched and rotated by a power transmission protrusion 210 formed in the power transmission rotation unit 200; a bobbin case base 700 having a female portion 710 fitted into a male portion 120 formed on a part of the inner circumference of the other side of the housing 100 and inserted into the hook body 300 from the other side of the housing 100 to the one side not to rotate about the hook body 300; a bobbin 400 rotatably inscribed to the bobbin case base 700; a cover 500 mounted to the bobbin case base 700 to inscribe to the bobbin case base 700 and circumscribe to the bobbin 400; a hook body separation preventing ring 600 rotatably circumscribed to the hook body 300 and preventing the hook body 300 from being separated from the one side of the housing in a state of being fixedly inscribed on the inner circumference of the one side of the housing 100; and a bobbin case base separation preventing ring 800 rotatably circumscribed to the bobbin case base 700 with a gap through which a needle thread 36 can pass and fixed to be in contact with the hook body 300 in a state of inscribing to the inner circumference of the other side of the housing 100 such that the bobbin case base 700 is prevented from being separated from the other side of the housing 100.

Thus, the bobbin case base separation preventing ring 800, the hook body 300, and the power transmission rotation unit 200 are to rotate together about the rotation axis L.

Moreover, the housing 100 has a hole 110 that is cut away on a part of the circumference thereof such that a needle 35 reciprocating vertically along a traveling path vertically crossing the rotation axis L can enter.

The hook body 300 has a taper-shaped hook 310 formed on the outer circumference in a state that an empty space communicating the hole 110 is formed in the downstream in the rotational direction, and the hook 310 captures a needle thread 36 of the needle 35 entered before the hook 310 via the hole 110 due to the rotation of the power transmission rotation unit 200.

The vertically fully rotation shuttle captures the needle thread 36 of the needle 35 passed through the respective cloth and descended, with the hook 310 rotated by the rotation of the power transmission rotation unit 200 at the same time when the clothes to be sewed are transmitted in the overlapped onto the through-hole 110 of FIG. 4, guides the needle thread 36 along a one side guide outer circumference 320 of the hook body 300 through a gap between the bobbin case base 700 and the bobbin case base separation preventing ring 800 to do a thread jumping with respect to the bobbin case base 700, and winds the needle thread 36 around the bobbin thread 34, such that a stitch is formed above the through-hole 110 of FIG. 4 in each cloth.

FIG. 7 is a view schematically illustrating a process of forming a stitch when two sheets of cloth are advanced forward and sewed using the vertically fully rotating shuttle.

The needle thread 36 that is fed by a thread take-up lever (not shown), is inserted into the insertion through-hole of the needle 35 from the other side (a front side in FIG. 7) of the housing 100 to one side (a rear side in FIG. 7) of the housing 100, and is guided up to the upper side of the upward cloth. The bobbin thread 34 is withdrawn from the bobbin case base 700, is guided to the other side of the housing 100 rather than the traveling path of the hook 310, and thus is guided down to the lower side of the lower cloth.

As illustrated at the very left side of FIG. 7, it is configured such that, when the needle 35 reciprocating up and down descends, the rotating hook 310 is disposed at the other side of the housing 100 than the needle 35, penetrates and captures the loop of the needle thread 36 at the upstream in the rotational direction of the hook 310 prior to the bobbin thread 34 to draw and increase the loop of the needle thread, a feeding thread portion 36 a of the needle thread 36 is guided to the book body 300 at the other side of the housing 100 and the lower side of the bobbin case base 700, a stitch-sided thread portion 36 b of the needle thread 36 goes over the one side guide outer circumference 320 of the hook body 300 and is guided to one side 720 of the bobbin case base 700, the feeding thread portion 36 a of the needle thread 36 turns around the bobbin thread 34, and as illustrated at the second left side of FIG. 7, the needle thread look jumps with respect to the bobbin case base 700.

At the same time when the needle thread loop jumps the bobbin case base 700, the thread take-up lever pulls the feeding thread portion 36 a of the needle thread 36 upwards in order to decrease the needle thread loop, and as illustrated at the second right side of FIG. 7, the needle thread 36 is wound and inserted by the bobbin thread 34. Due to further ascending of the thread take-up lever, as illustrated at the very right side of FIG. 7, the bobbin thread 34 and the needle thread 36 are wound and locked to each other near the seams of the respective cloth and then stitches are formed. By repeat of forming a series of strand, two sheets of cloth are sewed by the continuous final stitched 38.

Thus, according to the vertically fully rotating shuttle, since the feeding thread portion 36 of the needle thread 36 turns around the bobbin thread 34 and the needle thread loop jumps, the completed stitch becomes a lock stitch and uniform quality of sewed products can be obtained.

Furthermore, according to the vertically fully rotating shuttle of the present invention, when viewing in the direction where the bobbin thread 34 is stitched as illustrated at the very right side of FIG. 7, the needle thread 36 surrounds around the bobbin thread 34 from downstream to upstream to twist and form a not-opened ring-shaped stitch, a portion of the needle thread 36 covering the bobbin thread 36 from the very above the respective stitches exists, the bobbin thread 34 cannot squeeze between the loops of the needle thread 36, so that, as illustrated at the right side of FIG. 8, the final stitch is not released when any one of the needle thread 36 and the bobbin thread 34 is cut off or the needle thread 36 is pulled and tensed. 

1. A vertically fully rotating shuttle comprising: a fixed housing (100); a hook body (300) rotatably installed in the housing (100) to rotate about a rotational axis vertical to a travelling path of a needle reciprocating; a bobbin case base (700) inserted into the hook body (300) not to rotate about the hook body (300); and a bobbin (400), around which bobbin thread (34) is wound, detachably mounted to the bobbin case base (700); wherein the hook body (300) comprises a hook (310); wherein the hook (310) is disposed at the other side of the housing (100) rather than a needle (35), penetrates and captures a loop of a needle thread (36) at the upstream in the rotational direction of the hook (310) prior to a bobbin thread (34), a feeding thread portion (36 a) of the needle thread (36) turns around the bobbin thread (34) such that the loop of the needle thread jumps with respect to the bobbin case base (700).
 2. The vertically fully rotating shuttle of claim 1, further comprising: a hook body separation preventing ring (600) rotatably circumscribed to the hook body (300) in a state of fixedly inscribed to an inner circumference of one side of the housing (100) and preventing the hook body (300) from separating from one side of the housing (100); and a bobbin case base separation preventing ring (800) rotatably circumscribed to the bobbin case base (700) with a gap through which the needle thread (36) passes in a state of fixedly inscribed to an inner circumference of the other side of the housing (100), and coming into contact with and being fixed to the hook body (300) such that the bobbin case base (700) is prevented from separating from the other side of the housing (100).
 3. A stitch formed by a needle thread of a needle provided in a sewing machine or an embroidering machine and moving up and down, and by a bobbin thread provided in a vertically fully rotating shuttle, wherein, in the direction where the bobbin thread is stitched, the needle thread surrounds the bobbin thread from downstream to upstream and is twisted to form a ring-shaped stitch.
 4. A stitching method of stitching an object to be stitched using a needle thread wound around a needle thread bobbin provided in a sewing machine or an embroidering machine and a bobbin thread of a bobbin case base installed in a vertically fully rotating shuttle, the method comprising: penetrating and capturing a loop of the needle thread prior to the bobbin thread when a needle reciprocating up and down descends and drawing the loop of the needle thread to form a bigger loop of the needle thread; turning a feeding thread portion of the needle thread around the bobbin thread and thread-jumping the loop of the needle with respect to the bobbin case base; winding the needle thread around the bobbin thread and inserting the needle thread into the bobbin thread by pulling the feeding thread portion of the needle thread upwards in order to decrease the loop of the needle thread; and further pulling the feeding thread portion of the needle thread upwards such that the bobbin thread and the needle thread are wound and locked near seams of the object to be stitched. 